The invention relates to a method and a device for detecting a degree of pollution of an operational converter.
When converters, for example frequency converters, are operated in an environment which is polluted but for which they do not have a corresponding protection grade, deposits are formed inside the converter. Since the ambient air of the converter is used as a coolant, the dust particles contained in the ambient air can deposit on surfaces of the converter's components, especially elements to be cooled. For surfaces to be cooled, for example of a heat sink or surfaces of lossy components, these deposits lead to overheating with subsequent failure. Deposits on insulating surfaces can bridge the electrical insulation and therefore endanger the function and safety of the converter.
Whether a converter put on the market is used according to its protection grade can no longer be checked by the manufacturer of this converter. Only when a converter has shut down owing to the occurrence of a fault and technicians open this converter in order to remedy the fault, can it be established whether this converter has been used according to its protection grade. If not, the components of the converter must be covered with deposits. Only then is it established that the cause of the shutdown of the converter is not due to design but due to use. When such a converter is incorporated in a production process, the entire production sometimes has to be interrupted because of the converter which has shut down, which entails significant consequential costs.